Chapter 1 - 1.7 - Linear Inequalities in One Variable - 1.7 Exercises - Page 138: 84

$|x+6|\leq7$

$|u|\lt a~↔~-a\lt u\lt a$ $|u|\leq a~↔~-a\leq u\leq a$ $|u|\gt a~↔~u\lt-a~or~u\gt a$ $|u|\geq a~↔~u\leq-a~or~u\geq a$ The numbers must be greater than or equal to -13 and less than or equal to 1: $-13\leq x\leq1$ $-13+6\leq x+6\leq1+6$ $-7\leq x+6\leq7$ $|x+6|\leq7$